Field of the Invention
The present disclosure relates to an image processing apparatus configured to process an image of an eye, and a method of operating such an image processing apparatus.
Description of the Related Art
In a medical field, when some medical procedure is performed on a patient, a follow-up observation thereafter, that is, observing a reaction over time to the medical procedure is very important. In the field of diagnostic imaging, to make it easier to perform the follow-up observation, it is known to use a subtraction image, which is an image generated by determining a difference between a plurality of captured images obtained by capturing images of an object at different times. In a radiographic imaging field, Japanese Patent Laid-Open No. 2002-230517 discloses a subtraction image of chest X-ray images captured at different times.
In an ophthalmic field, Japanese Patent Laid-Open No. 04-336677 discloses a subtraction image of a fundus under examination between images captured at different times.
As for an imaging apparatus for use in the ophthalmic field, it is popular to use an optical coherence tomography (OCT) apparatus using interference of low coherence light. Regarding the follow-up observation using images captured using the OCT apparatus, Japanese Patent Laid-Open No. 2010-220771 discloses a method in which fundus images and tomographic images of a fundus captured at different times are displayed side by side on a monitor. Japanese Patent Laid-Open No. 2010-220771 also discloses a method in which difference information representing a difference in layer thickness distribution between tomographic images is displayed as layer thickness information in the form of a graph on a monitor.